48.7 Animation Objects

Nam does animation using the following building blocks which are defined below:

Nodes are created from 'n' trace event in trace file. It represents a source, host, or router. Nam will skip over any duplicate definitions for the same node. A node may have three shapes, (circle, square, and hexagon), but once created it cannot change its shape. Nodes can change its color during animation. Nodes can be labeled.

Links are created between nodes to form a network topology. Internally nam links are consist of 2 simplex links. The trace event 'l' creates two simplex links and does other necessary setup. Therefore, for a users perspective all links are duplex links. Links can be labeled and also can change color during the animation. Links cab be labeled as well.

Queues need to be constructed in nam between two nodes. A nam queue is associated to only one edge of a duplex link. Queues are visualized as stacked packets. Packets are stacked along a line, the angle between the line and the horizontal line can be specified in the queue trace event.

Packets are visualized as a block with an arrow. The direction of the arrow shows the flow direction of the packet. Queued packets are shown as little squares. A packet may be dropped from a queue or a link. Dropped packets are shown as falling rotating squares, and disappear at the end of the screen. Unfortunately, due to nam's design dropped packets are not visible during backward animation.

Agents are used to separate protocol states from nodes. They are always associated with nodes. An agent has a name, which is a unique identifier of the agent. It is shown as a square with its name inside, and is drawn next to its associated node.
Tom Henderson 2011-11-05